Drive

"Open the Google Drive website in your desktop’s web browser and select one or more files or folders. You can use the Control key on Windows, or Command key on Mac, to select non-consecutive files and folders. Now press Shift + Z and you’ll see an “Add to Folder” pop-up (see screenshot, link above). Next select the folder where you wish to add the selected files and click OK.

That’s it. You have neither copied nor moved the files to the destination folder, you’ve merely created references or aliases to files inside the other folder. You can use the Shift+Z keyboard shortcut again to add the selected files to any other folders in your Google Drive."